The present invention comprises a new and distinct cultivar of calla lily, botanically known as Zantedeschia sprengeri and hereinafter referred to by the cultivar name ‘Red Charm’.
‘Red Charm’ is a product of a planned breeding program, which had the objective of creating Zantedeschia hybrids for pot flower production in a wide range of colors with a large, classic flower shape. The breeding program began in 1989, and the new cultivar is a seedling selected from the crossing of a Zantedeschia sprengeri seedling referred to as Z051059 (female parent, unpatented) with a Zantedeschia sprengeri seedling referred to as Z041373 (male parent, unpatented). ‘Red Charm’ was selected in 2009 by the inventor in 't Zand, The Netherlands as one flowering plant within the progeny of the stated cross.
The first act of asexual reproduction of ‘Red Charm’ by tissue culture was performed by the inventor in September of 2009 in 't Zand, The Netherlands. Subsequent asexual reproductions by tissue culture at the same location have demonstrated that the combination of characteristics as herein disclosed for the new cultivar are retained and reproduced true to type through successive generations of asexual reproduction.
The following observations, measurements and comparisons describe plants grown in a 14 cm pot at 12-14 weeks after planting in 't Zand, The Netherlands under greenhouse conditions, which approximate those generally used in horticultural practice. Color references are made to The 2001 R.H.S. Colour Chart of The Royal Horticultural Society of London, except where general color terms of ordinary significance are used.
The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.
The following traits have been repeatedly observed and determined to be basic characteristics of ‘Red Charm’ which, in combination, distinguish this calla lily as a new and distinct cultivar:                1. Red-colored spathe;        2. Red-colored leaf margin; and        3. High inflorescence production.        
Further, when compared to calla lily plant named ‘Black Star’ (U.S. Plant Pat. No. 14,844), the upper and lower surface spathe color of ‘Black Star’ varies between Greyed-Purple Group RHS 187A and Black Group RHS 202A, while the upper surface spathe color of ‘Red Charm’ varies between Greyed-Purple Group RHS 187B and 187C and the lower surface spathe color varies between Greyed-Purple Group RHS 186C and 187B.
Table 1 provides similarities and differences of ‘Red Charm’ to its parents, Zantedeschia sprengeri seedlings Z051059 and Z041373.
TABLE 1‘Red Charm’SimilaritiesDifferencesZ051059Spathe shapeSpathe color (Between Greyed-Purple Group RHS N187A andBlack Group RHS 202A)Plant height (10-35 cm)Z041373Number of inflorescencesSpathe shape (Funnel)Plant heightSpathe color (Between Orange-Red Group RHS 34A and N34A)